2025 Fall Drawdown Schedule

Posted on 15 September 2025 in News

The Mississippi Valley Conservation Authority’s annual fall drawdown will begin later this month. This seasonal water level management helps prepare the watershed for spring runoff and reduces the risk of flooding. The drawdown schedule is as follows:

  • Shabomeka Lake, Pine Lake, and Mississippi Lake: Drawdowns will begin in late September.
  • Summit Lake and Widow Lake: Drawdowns will start after the Thanksgiving weekend.
  • Kashwakamak Lake, Mississagagon Lake, and Big Gull Lake: Scheduled to begin in late October.
  • Mazinaw Lake: Drawdown will be delayed until early November to allow for continued boat traffic through the narrows during hunting season.

Winter target levels are typically reached before freeze-up, though the timing may vary depending on fall rainfall across the watershed. Current forecasts indicate that conditions over the next two months are expected to be at or below seasonal averages. The chart below outlines the drawdown dates for lakes used to provide flood storage for the upcoming spring season.

Lake / DamDrawdown Start DateDrawdown End Date
Shabomeka Lake DamLate SeptemberEarly October
Pine Lake DamLate SeptemberEarly October
Mississippi Lake / Carleton Place DamLate SeptemberMid October
Kashwakamak Lake DamLate OctoberMid December
Mississagagon Lake DamLate OctoberMid November
Big Gull Lake DamLate OctoberMid November
Summit Lake DamAfter Thanksgiving weekendLate October
Widow Lake DamAfter Thanksgiving weekendLate October
Mazinaw Lake DamAfter hunting season (Mid November)Mid December

Residents are urged to use extreme caution around these structures as strong currents will be present while water levels decrease to normal fall levels during this time and should ensure that all boats, floating docks, etc., have been removed. 

Daily water levels and flows are available on the MVCA website at mvc.on.ca/water-levels/

CONTACT:
Juraj Cunderlik, Ph.D., P.Eng.
Director, Engineering
613-253-0006 ext. 233
jcunderlik@mvc.on.ca